You don't say whether he is nuetered or whether this is a new behavior. I am assuming that because you have had him for 5 months, that his peeing and pooping in bad places is something new.
When we see inappropriate peeing and pooping it is most often a sign of illness. So, the first thing you need to do is to take your cat to the vet and tell the vet what he is doing. This way the vet will know to sample the cat's urine and feces to see whether he is ill. If your cat is sick, then medications should stop the problem.
If the vet finds that your cat is healthy, please click here
and then click on the two threads which discuss inappropriate urination and poop problems. These threads will tell you how to solve these problems.
But -- and this is very important -- if your cat is not neutered, it is likely that he is peeing and pooping on your stuff to mark his territory. Once he is neutered this behavior will almost certainly go away.